LOS ANGELES -- Concert movies typically offer a peek into the private moments of a pop star's life. "Michael Jackson: This Is It" revealed the entertainer's perfectionist tendencies, and sly sense of humor. "Justin Bieber: Never Say Never" showed the teen singer's drive for success.

But "Glee: The 3D Concert Movie," opening Friday, is an 83-minute romp with the fictional characters who populate the Fox TV series. It's multi-purposing at its finest: Stars Lea Michele, Cory Monteith, Kevin McHale, Chris Colfer, Amber Riley, Heather Morris and the rest maintain their "Glee" personae while performing hits from the show during the concert tour that traveled the country earlier this summer.

And that's what sets it up for success, says director Kevin Tancharoen.

"It would have been completely disconnected from what made (the show) extremely popular if it had turned into, 'Oh, look at Lea Michele and Cory Monteith and Harry Shum Jr. be superstars and rehearse and do press and record and go on tour,'" Tancharoen said.

"That's why I think it's different from those other concert films," he continued. "Those are all rock stars and musicians, and these are characters who mean something different to everybody else. They are extremely talented and they all sing very well and perform very well, and that's another big part of the show that was very popular, so we kind of wanted to mix all that stuff together to make this 3-D concert experience."

In addition to on-stage performances of songs such as "Teenage Dream" and "I'm a Slave 4 U," the film also shows its stars giving backstage interviews in character. In one segment, Michele's character, the spotlight-loving Rachel Berry, explains her pre-performance ritual of drinking "lukewarm hot water."

"I feel like I did a nice blend of Rachel and of Lea while I was onstage performing," Michele said Saturday.

"We are our characters, but at the same time when we walk on stage, we are ourselves."

Not so for Colfer: "I had to be in character because there was no way I could have done 'Single Ladies' every night," he said.

Fox says the film is aimed at fans of the "Glee" TV show, which regularly draws more than 10 million viewers a week.

Fans are a part of the film, too. "Glee: The 3D Concert Movie" introduces viewers to three young fans who share how the show's characters and storylines boosted their own self confidence.

Even folks who aren't fans of "Glee" can connect with the film, since its music spans generations "and it's all about storylines that you are learning right as you are watching the film," the director said.

And completing the multi-purposing thing, maybe those folks become series fans, too, says Fox Television Chairman Dana Walden.

"For families or for parents trying to get a sense of what the phenomenon is about, (they'll) be able to see songs from the parents' generation that have been reinvented a little bit so the kids can feel like it's relevant to them as well," she said.

"The feature has similar attributes: Great music, contemporary dance, and these characters that can be introduced to parents or grandparents."

Walden said she was inspired by Bieber's successful rock doc, which raked in more than $70 million at the box office.

"That was an indicator for me that this is a great idea; there is an audience for this," she said.

"I would be satisfied if the attendance reflected the excitement we've seen surrounding the film."